1. Field of the Invention
This invention relates to a manufacturing process of an anti-vibration device used as an engine mount and the like for mounting an engine of an automobile on a vehicle body with an aim of isolating the vibration.
2. Description of the Prior Art
It is well known to provide such an engine mount comprising an elastic member generally of a truncated cone shape when viewed from a side, a first mounting, member is connected to an upper side thereof, a second mounting member is connected to a lower side thereof, and a stopper projection projects from the first mounting member in a side direction to be able to abut to an about a half round side portion of the elastic member. A stopper member extends from the second mounting member through an outer portion of the stopper and projects to the first mounting member side to cover the half round side portion of the elastic member and forms a stopper receiving portion in which an apex portion thereof is bent to overlap on the stopper projection with a specified gap between the stopper projection and the stopper receiving portion. (For example, such a device is disclosed in Japanese Laid-Open Patent Publication (Kokai) No. Hei8-177956, Hei8-270716, Hei8-320048 and Hei8-338471.)
To manufacture the engine mount, at first, the first mounting member that is not mounted the stopper projection and the second mounting member that is not formed on the stopper receiving portion were integrated by baking with rubber such as the elastic member. Thereafter, the stopper projection is attached on the first mounting member and the stopper member is attached on the second mounting member to overlap the stopper receiving portion on the stopper projection with a specified gap in a center line direction of the elastic member.
It is well known to overlap each peripheral portion of two circular members provided in such an engine mount, to arrange a metal-made ring member for caulking along an outer peripheral portion, to bent the ring caulking member to be in U-shaped section and to connect the peripheral portion of the two circular members by caulking.
Further, it is well known to use a liquid sealed type anti-vibration rubber device for such an engine mount. There is generally provided a device comprising a first mounting member secured to one side of either a vehicle body or a vibrating member, a second mounting member secured to the other side of a vehicle body or a vibrating member, an elastic member connected between the first and second mounting member shaped in a partially cylindrical having a concave portion disposed therein and being opened an end portion thereof, a diaphragm closing an opened portion of the concave portion so as to form a liquid chamber filled with liquid between the elastic member therewith, a partitioning wall for dividing the liquid chamber into two chambers as a main liquid chamber, and a sub liquid chamber and an orifice for communicating between the two liquid chambers.
In order to assemble the liquid sealed type anti-vibration rubber device, in advance, a top side assembly integrated with the first mounting member and the elastic member, and a bottom side assembly integrated with the second mounting member and the diaphragm, are formed and each assembly is immersed into a liquid bath filled with filling liquid.
While controlling the liquid volume to be charged with the specified value in the liquid bath, the bottom side assembly is fitted in an end portion of a cylindrical metal member and the top side assembly and the bottom side assembly are mounted to a liquid sealing jig while keeping the fitting condition thereof.
Thereafter, the top side assembly and the bottom side assembly are taken out from the liquid bath in the state of being fitted to the liquid sealing jig and secured to a roll caulking machine at the outside of the liquid bath. Then, the bottom side assembly and top side assembly are connected by roll caulking an apex portion of the cylindrical metal member in the state of removing the fluid sealing jig.
In this case, an end portion of the cylindrical metal member provided on a peripheral portion of the elastic member is made to be a connecting portion fixing the partitioning member and the diaphragm by caulking, the elastic member side is immersed into liquid in a stage before caulking the connecting portion and liquid is charged into the inner main liquid chamber side. The partitioning member and the diaphragm are accommodated inside of an end portion of the cylindrical metal member. After taken out from the liquid bath, the end portion of the cylindrical metal member is adapted to be caulked with the partitioning member and the diaphragm.
In the case of a construction providing said stopper member, when the stopper member is secured in another process after forming of the elastic member, since it is required to take a means of welding or bolt fastening, it is difficult to ensure a precision control concerning to the retaining dimensions between the first mounting member and the stopper receiving portion.